Blower wheel center plate with bent tabs for securing blades in place



June 17, P, JQLETTE BLOWER WHEEL CENTER PLATE WITH BENT TABS FOR SECURING BLADES IN PLACE Filed Aug. 4, 1967 INVENTOR. 666410 JOLU7 XML w gm United States Patent 3,450,337 BLOWER WHEEL CENTER PLATE WITH BENT TABS FOR SECURING BLADES IN PLACE Gerald P. Jolette, Kalamazoo, Mich., assignor to The Brundage Company, Kalamazoo, Mich., a corporation of Michigan Filed Aug. 4, 1967, Ser. No. 658,456

Int. Cl. F04d 29/28 US. Cl. 230-134 7 Claims ABSTRACT OF THE DISCLOSURE Field 09 the invention This invention relates to centrifugal fans and more particularly to means for securing a support plate to the cage of a blower wheel whereby radial restraint and driving power may be imparted to the blades.

Description of the prior art It has been standard practice for many years to provide a support plate of some type for the mounting of a blower wheel directly to a driving shaft such as the shaft of a motor. Commonly, the support plate is secured to the blades at a point intermediate the rims. It is important in the construction of such blower wheels to retain proper positioning and alignment of the blades under all operating conditions and to maintain vibration and noise levels at a minimum. In order to do so, the blades must be held rigidly by the support plate. Various approaches for securing the blades to the support plate have been suggested in the past but such approaches have been either complicated, unreliable, or uneconomical and thus not completely satisfactory. For example, several attempts have made to construct the support plate of a pair of coa'cting disks. In one such approach, a first disk has a plurality of hooks, each of which extends over a portion of the adjacent blade. The second disk has a protuberance Which is collapsed after positioning of the disks against the blade, thereby causing the circumference of the disk to expand and forcing the blades outwardly against the hooks of the first disk. Such an approach is both expensive and complicated. Another attempt has utilized a pair of coacting disks having oppositely facing hooks which effect a locking engagement with slots in the blades by rotating the disks in opposite directions. This structure is also not entirely satisfactory from an economic standpoint. In other instances, the blades have been spot welded to the support plate in which case a weld has been known to break permitting the blade to vibrate against the support plate.

Accordingly, in overcoming the above problems, it is an object of this invention to provide a blower wheel of the centrifugal multiple blade type wherein each blade of the wheel is securely engaged with the center plate.

Another object is to provide a blower wheel, as aforesaid, which has means for radially restraining the blades, thereby resulting in an economical, strong and rigid wheel.

A further object is to provide a blower wheel having a 3,450,337 Patented June 17, 1969 support plate comprised of a single disk, said disk having a plurality of hooks or tabs, each of which is securely engaged by simple means with the blade of the blower wheel.

A further object of the invention is to provide a blower wheel having an improved means for rigidly connecting the blades with the support plate.

A still further object of the invention is to provide a simple, inexpensive, yet dependable method of securing the blades to the support plate.

Other objects and purposes of this invention will be apparent to those persons acquainted with apparatus of this general type upon reading the following specification and inspecting the accompanying drawings, in which:

FIGURE 1 is a perspective view of a blower wheel.

FIGURE 2 is a cross-sectional view of the blower wheel of the present invention taken along the line II-II in FIGURE 1.

FIGURE 3 is a side view of the blade-securing means taken along the line III-III in FIGURE 2.

FIGURE 4 is a front view of the blade-securing means.

FIGURE 5 is a sectional view taken along the line V-V in FIGURE 4.

Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words upwardly, downwardly, rightwardly and leftwardly will designate directions in the drawings to which reference is made. The words forwardly and rearwardly will refer to the rightward and leftward directions, respectively, of the invention as appearing in FIGURE 3. The words inwardly and outwardly will refer to directions toward and away from, respectively, the geometric center of the device and designated parts thereof. Said terminology will include the words above specifically mentioned, derivatives thereof and words of similar import.

Description of the preferred embodiment The blower wheel 10 (FIGURE 1) is comprised of a cage 11 and a support plate, which in the preferred embodiment, is the center plate 12. The cage 11 may be of any conventional type, but may, as here illustrated be formed as a one-piece integral unit. Same has a pair of rims or rings 13 and 14 and a plurality of impeller blades 16, said blades extending between and being in this embodiment integral with rims 13 and 14. A fiat rectangular portion of sheet metal may be stamped to define a plurality of evenly spaced blades of arcuate cross-sectional form. The sheet may be bent or rolled into a cylindrical shape with the abutting ends being secured together, such as by welding, and the remaining raw edges being rolled, as is well known, to form rims 13 and 14 or alternatively other conventional rims may be secured thereto.

The support plate 12 (FIGURES 1 and 2), in this instance a center plate, is circular in shape having a concave central portion 17 which provides increased rigidity and strength and a plurality of radially extending hooks or tabs 18, one such tab being provided for engagement with each of the blades 16. A hub 19 is secured in the center of plate 12 for the mounting of the blower wheel 10 onto a shaft, such as the shaft of a driving motor (not shown). Hub 19 is illustrated as having a set screw 21 for providing a locking engagement between blower wheel 10 and the driving shaft.

The tabs 18 (FIGURE 3) have a radially and forwardly extending body portion 22, the forward edge 23 of which is arcuately shaped to conform with the desired shape of the blades 16 and to provide load bearing contact with said blade. A tip portion 24, only one being used in this embodiment with each of tabs 18, extends forwardly of portion 22 through a slot or opening 26 in blade 16. Said tip portion 24 (FIGURES 3, 4 and 5) is securely locked in opening 26 by twisting of same. For example where such twisting is done manually, it may be by grasping body portion 22 with a first pliers to prevent distortion of portion 22 and then grasping portion 24 with a second pliers and twisting axially and/ or bending same sidewardly. The tip portion 24 is thereby caused to be tightly lodged in opening 26 and blade 16 is pressed tightly, and locked, against the forward edge 23 of the body portion 22. Alternatively, tip portion 24 may be twisted and/ or bent by other mechanical means.

The same procedure is repeated successively or simultaneously for each tip-and-blade group and the wheel parts thereby assembled firmly together.

Where multiple tips are used on each of tabs 18, such as on larger wheels, they may be bent, or twisted, in directions opposite to each other to improve the locking and balancing thereof. Also when single tips are used, same may all be bent or twisted in the same direction or they may be bent or twisted alternately in opposite directions.

Although a particular preferred embodiment of the invention has been disclosed above for illustrative purposes, it will be understood that variations or modifications thereof which lie within the scope of the appended claims, are fully contemplated.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A centrifugal blower wheel comprising:

a cylindrically shaped cage means having a plurality of substantially parallel uniformly spaced blades interconnected at their respective ends, each of said blades having defined therein a slot; and

at least one support member including a plate having a plurality of tabs, each of said tabs having a part thereof fixed to the plate and positioned adjacent one side of the corresponding adjacent blade of said cage means, each of said tabs further having a tip port-ion fixed to said part and extending through the slot of the corresponding adjacent blade so as to be positioned adjacent the other side thereof, said tip portion being deformed relative to said part and relative to said blade whereby said deformed tip portion substantially defines a plane which intersects the plane defined by said part, thereby providing a locking engagement between said support member and said cage means.

2. A centrifugal blower wheel as defined in claim 1, wherein each of said tabs extends radially from said plate and said tip portion extends substantially circumferentially through said slot, said tip portion being twisted axially causing locking engagement.

3. A centrifugal blower wheel as defined in claim 1,

wherein each of said tabs extends radially from said plate and said tip portion extends substantially circumferentially through said slot, said tip portion being bent sidewardly causing locking engagement.

4. A centrifugal blower wheel comprising:

a cylindrically shaped cage means having a plurality of substantially parallel, arcuate blades disposed between coxial rim members, each of said blades having defined therein a transverse slot; and

a support means having a plate, a hub disposed in the center of said plate for driving engagement with a power means, and a plurality of tabs, each of said tabs having a body portion extending radially from said plate and positioned adjacent one side of an adjacent blade and having a tip portion which extends through the slot and is positioned adjacent the other side of the adjacent blade and is twisted relative to the slots of the adjacent blade so that said tip portion overlies a portion of said blade adjacent said slot for preventing separation of said blade from said plate, thereby providing driving engagement between said support means and said cage means.

5. A centrifugal blower wheel as defined in claim 4, wherein each of said tabs has an arcuately shaped forward edge which conforms to andbears against the arcuate shape of said blades thereby providing a driving contact on said blade by the entire arcuate forward edge of said tab.

6. A blower as defined in claim 4, wherein said tip is twisted both axially and sidewardly.

7. A centrifugal blower wheel as defined in claim 1, wherein said plate is positioned within said cylindrically shaped cage means and extends substantially radially thereof, said plurality of tabs being integrally connected to said plate with said tabs, except for said deformed tip portions, lying within a plane which is substantially transverse to the axial direction of said cage means.

References Cited UNITED STATES PATENTS 1,998,366 4/1935 Geyer S55.2 2,084,015 6/1937 Bronson l 5.2 2,626,741 1/1953 Osborne 230-1345 3,181,778 5/1965 Mayne 230134.5 3,335,482 8/1967 McClatchie 230134.5 2,272,695 2/1942 Evans 230-1345 HENRY F. RADUAZO, Primary Examiner.

U.S. C1. X.R. 29--156.8 

